Apparatus and method for high pressure abrasive fluid injection

Abstract

A system for injecting high pressure abrasive fluid into an abrasive jet tool in a wellbore comprises an abrasives hopper; a slurry tank connected to the abrasives hopper; a low pressure abrasive pump connected to the slurry tank; a first high pressure vessel connected to the low pressure pump through a first high pressure valve; a high pressure non-abrasive pump connected to the first high pressure vessel through a second high pressure valve; and an abrasive jet tool connected to the first high pressure vessel through a third high pressure valve.

The invention claimed is: 
     
       1. A system for injecting high pressure abrasive fluid into a wellbore, comprising:
 an abrasives hopper; 
 a slurry tank connected to the abrasives hopper; 
 a low pressure abrasive pump connected to the slurry tank, wherein the low pressure abrasive pump comprises abrasive-resistant materials; 
 a slurry circulation line for circulating slurry from the slurry tank through the low pressure abrasive pump past the abrasive hopper and back to the slurry tank; 
 a first high pressure vessel connected to the low pressure pump through a first high pressure valve; 
 a high pressure non-abrasive pump connected to the first high pressure vessel through a second high pressure valve, wherein the high pressure non-abrasive pump is configured to pressurize the first high pressure vessel; and 
 a wellbore connected to the first high pressure vessel through a third high pressure valve. 
 
     
     
       2. The system of  claim 1 , further comprising:
 a second high pressure vessel connected through a fourth high pressure valve to the low pressure abrasive pump and to the high pressure non-abrasive pump and connected through a fifth high pressure valve to the wellbore. 
 
     
     
       3. The system of  claim 1 , further comprising:
 a water supply tank connected to a line connecting the high pressure non-abrasive pump. 
 
     
     
       4. The apparatus of  claim 3 , further comprising:
 a flow restrictor connected to the high pressure non-abrasive pump and the water supply tank. 
 
     
     
       5. The apparatus of  claim 1 , wherein the first high pressure valve comprises a dump valve. 
     
     
       6. The apparatus of  claim 1 , further comprising:
 a pressure pulse damper connected to a line connecting the high pressure non-abrasive pump and the first high pressure valve; and 
 a pressure sensor connected to the pressure pulse damper. 
 
     
     
       7. The apparatus of  claim 1 , further comprising:
 a fluid discharge hose connecting the abrasives hopper to the slurry tank. 
 
     
     
       8. A method for injecting high pressure abrasive fluid into a well bore, comprising:
 mixing low pressure abrasive slurry by circulating the abrasive slurry from a slurry tank, through a low pressure abrasive pump, by an abrasive hopper, and back to the slurry tank, wherein the low pressure abrasive pump comprises abrasive-resistant materials; 
 circulating the low pressure abrasive slurry from the slurry tank, through the low pressure abrasive pump, through a second high pressure valve, through a first high pressure vessel, through a third high pressure valve, and back to the slurry tank; 
 sending high pressure non-abrasive fluid by a high pressure non-abrasive pump through a first high pressure valve to the first high pressure vessel; 
 opening the second high pressure valve to allow abrasive slurry to fill the first high pressure vessel; and 
 actuating the first, second, and third high pressure valves to allow the high pressure non-abrasive fluid to push the abrasive slurry through the first high pressure vessel to a wellbore. 
 
     
     
       9. The method of  claim 8 , further comprising:
 actuating the first, second, and third high pressure valves to allow more non-abrasive fluid
 to go directly to the wellbore while the high pressure non-abrasive pump refills the first high pressure vessel through the first high pressure valve. 
 
 
     
     
       10. The method of  claim 8 , further comprising:
 actuating the first, second, and third high pressure valves to allow abrasive slurry to fill a second high pressure vessel through a fourth high pressure valve; and 
 actuating the first, second, third, and fourth high pressure valves to allow the high pressure
 non-abrasive fluid to push the abrasive slurry through the second high pressure vessel and a fifth high pressure valve to the wellbore, while the non-abrasive high pressure pump refills the first high pressure vessel through the first and second high pressure valves. 
 
 
     
     
       11. The method of  claim 8 , further comprising:
 adding guar powder to the slurry tank to gel the abrasive fluid. 
 
     
     
       12. The method of  claim 8 , further comprising:
 adding air to the slurry tank.